You sound like someone who's reasoning with himself when he finds out he has stage 1 cancer. It's small, it can only do a little harm. We should just leave it alone and it'll go away.
Then it starts spreading, emboldened by its victories. Soon its forces are in the millions, larger than armies in the richest of countries. Then, double digit percentages of Muslims will believe in terrorism.... and it'll spread to every single country in the world that borders a Muslim country. Oh wait, it already has.
Oh and uh, only kill a couple hundred people? What if one of those people was a member of your family? Your dismissal of human life is not only disgusting but shocking since you consider yourself a liberal. ONE innocent life is ONE too many.